1. Field of the Invention
The present invention relates generally to mechanical press machines, and, more particularly, to a system including an assembly, such as a gear assembly, arranged to be driven by the press flywheel and connected in one form to a hydraulic pump that supplies a fluid flow to the press machine under the influence of the flywheel.
2. Description of the Related Art
Mechanical presses of the type performing stamping and drawing operations employ a conventional construction that includes a frame structure having a crown and bed portion and which supports a slide in a manner enabling reciprocating movement toward and away from the bed. A press drive assembly including a crankshaft having an arm assembly connected to the slide is arranged to convert rotary-oscillatory motion into the linear reciprocating motion of the slide. These press machines are widely used for a variety of workpiece operations employing a large selection of die sets, with the press machine varying considerably in size and available tonnage depending upon its intended use.
The loads developed during press operation put significant stresses on various machine parts such as the crankshaft which nevertheless must provide stable bearing support throughout the entire processing cycle. The integrity of this bearing support takes on added importance during high acceleration duty cycles designed to deliver substantial impact forces to the workpiece. It therefore becomes imperative that the press machine be provided with some form of lubrication system to supply the machine parts with a fluid flow sufficient to create a hydrostatic and hydrodynamic bearing support, for example. The fluid flow also serves to draw heat away from the machine parts so that the press equipment remains within its normal operating temperature range.
Conventional lubrication systems employ a hydraulic pump driven by a motor that is typically connected to the same power source used by the press motor. Although efficient in terms of minimizing the electrical requirements, this form of power sharing produces deleterious results when an electrical failure cuts off the energy supply to the machine, leaving not only the press machine inoperable but also the lubrication system. An unplanned interruption in the machining operation, however, may not produce irreparable harm to the workpiece since the power failure simply causes a suspension in the processing activity that can be successfully resumed once power is restored. However, the demands of the press machine associated with parts lubrication and heat dissipation must continue to be met in order to protect the machine from potential damage caused by overheating and structural degradation arising from the immediate loss of lubricating fluid. Replenishing the hydraulic fluid flow in a timely manner represents a priority for the machine operator during power failure. This may be accomplished by reactivating the lubrication system using a backup power source or immediately diagnosing and fixing the problem in the main power supply. Both techniques, however, are time consuming and require the integration of an auxiliary power device or, alternatively, the construction of an automatic power diagnostic unit that must provide a real-time solution to the problem.